Continuing disagreements over the westward expansion of slavery increased the tensions between the North and the South. A democrat from Pennsylvania said that any territory that the U.S. gains from Mexico should be free and against slavery. But the South believed that any antislavery policies anywhere would effect the slavery everywhere else. The government decided that the citizens of every new territory should have the right to decide for themselves so they were able to vote. This idea was called popular sovereignty .
Continuing disagreements over the westward expansion of slavery increased the tensions between the North and the South. A democrat from Pennsylvania said that any territory that the U.S. gains from Mexico should be free and against slavery. But the South believed that any antislavery policies anywhere would effect the slavery everywhere else. The government decided that the citizens of every new territory should have the right to decide for themselves so they were able to vote. This idea was called popular sovereignty .